1. Field of the Invention
The present invention relates to an image display apparatus such as an image network system, a medical work station, and the like.
2. Description of the Related Art
When two, e.g., old and new images obtained by imaging an identical patient are visually compared, whether an anomalous substance in the two images corresponds to a pulmonary carcinoma or the section of a blood vessel is determined with reference to the size of the ROI, and a degree of blurring of a portion around the ROI. A doctor compares a tumor size and a region of interest on a film. However, input original image data do not always have a constant pixel size, and display screens of CRT displays used as display means do not always have a constant pixel size.
Therefore, in a conventional image display apparatus, even if a plurality of original image data to be displayed have a constant pixel size in units of original image data, images are displayed while being reduced or enlarged in proportion to the display sizes (inch sizes) of CRT displays to be used. For example, a display screen of a 19" CRT display having a 1,000.times.1,000 pixel matrix has a vertical size of about 40 cm, and a display screen of a 15" CRT display having a 1,000.times.1,000 pixel matrix has a vertical size of about 24 cm. Such a difference in size between the display screens changes the size of an image to be displayed.
For this reason, it is difficult to directly observe a plurality of images displayed on CRT displays and to compare and judge ROIs in images. Therefore, a plurality of images displayed on the CRT displays are developed on a film, and the above-mentioned judgment is made using the film. But, the above-mentioned judgement has not enough been put into practical use.
A scale may be displayed in the vicinity of an image displayed on the CRT display. With reference to this scale, the sizes of a plurality of images are converted to the same unit in mind, so that the plurality of images to be compared have the same size, thus making the above-mentioned judgment.